Resin composition for color filter

ABSTRACT

A resin composition for a color filter is provided which can surely prevent the occurrence of display failures (unacceptable display phenomena) of color liquid crystal display devices, can broaden a range of selection of usable constituent materials, and does not incur increased cost. The resin composition for a color filter comprises a combination of a volatile component with a nonvolatile component, wherein: not less than 50% by weight of the nonvolatile component is accounted for by a first constituent, which, after the impurity extraction of a liquid crystal, permits the liquid crystal to have a voltage retention of not less than 60% and to have a residual DC (ΔE) of not more than 0.6 V; and when less than 50% by weight of the nonvolatile component is accounted for by a second constituent, which, after the impurity extraction of a liquid crystal, cannot permit the liquid crystal to have a voltage retention of not less than 60% and to have a residual DC (ΔE) of not more than 0.6 V, a requirement represented by formula (1) for the relation between the content of the second constituent and the voltage retention and a requirement represented by formula (2) for the relation between the content of the second constituent and the residual DC are satisfied: 
     Content (wt %)÷voltage retention (%)&lt;0.1  (1) 
     Content (wt %)×residual DC (V)&lt;5  (2).

TECHNICAL FIELD

[0001] The present invention relates to a resin composition for a colorfilter, and more particularly to a resin composition which can realize aliquid crystal display device having excellent display quality.

BACKGROUND ART

[0002] In recent years, color liquid crystal display devices have drawnattention as flat displays. One example of the color liquid crystaldisplay devices is a transmission liquid crystal display device suchthat a color filter comprising a black matrix, a colored layer of aplurality of colors (in general, the three primary colors of red (R),green (G), and blue (B)), a common transparent electrode layer, and analigning layer is provided so as to face a counter electrode substratecomprising a thin film transistor (a TFT device), an pixel electrode,and an aligning layer, while leaving a predetermined gap between thecolor filter and the counter electrode substrate, and a liquid crystalmaterial is poured into the gap to form a liquid crystal layer. Anotherexample of the color liquid crystal display devices is a reflectionliquid crystal display device wherein, in the above color filter, areflective layer is provided between the substrate and the coloredlayer.

[0003] In these color liquid crystal display devices, a change in thestate of alignment of the liquid crystal caused, for example, by analignment failure of the liquid crystal, a change in voltage applied tothe liquid crystal, and a variation in voltage within the displaysurface, results in the occurrence of display failures (unacceptabledisplay phenomena) which are classified into sticking and unevenwhiteness.

[0004] Sticking is a phenomenon such that, when a voltage has beenapplied to an identical pixel for a given period of time followed by alowering in voltage or the stop of the application of the voltage, thetransmittance of this pixel becomes different from the transmittance ofpixels, located around this pixel, to which the voltage has not beenapplied for the given period of time, and, as a result, an unevendisplay is visually perceived and is continued even after standing for along period time. In the sticking phenomenon of normally white panels,the pixel, to which a voltage has been applied for a given period oftime, is seen more darkly than pixels located around this pixel. Thissticking phenomenon is attributable to the fact that an ionic materialis deposited on an electrode during the application of the voltage and,after the stop of the application of the voltage, remains adsorbed onthe electrode and, as a result, the voltage derived from the ionicmaterial continues to act on the liquid crystal.

[0005] On the other hand, uneven whiteness is a phenomenon such that anuneven display is visually perceived due to the fact that, when avoltage is applied to display a black screen, the transmittance does notbecome zero in a part of the display region. The cause of thisphenomenon is considered as follows. Although the voltage applied acrossthe electrodes should be kept constant, when an ionic material ispresent in the liquid crystal, this ionic material is moved, that is, acurrent flows, resulting in a drop of voltage across the electrodes.

[0006] Techniques which have taken the above display failure phenomenainto consideration include a technique relating to ionic impuritiescontained in a material composition for liquid crystal devices (JapanesePatent Laid-Open No. 254918/1989), a technique relating to chloride ionsand nitrate ions contained in a material composition for liquid crystaldevices (Japanese Patent Laid-Open No. 64619/1999), and a techniquerelating to the amount of water generated from color filters (JapanesePatent Laid-Open No. 133223/1999).

[0007] In the prior art techniques, however, target ionic impurities andconstituent materials are limited. This poses a problem that thepresence of impurities other than the target impurities and theinclusion of impurities in constituent materials other than the targetconstituent materials result in display failures of color liquid crystaldisplay devices. Further, in the resin composition used in theproduction of color filters, the kind and amount of impurities varydepending, for example, upon the kind of constituent materials,manufacturers, and names of articles. This has made it difficult topredict the influence of a change in constituent materials on displaycharacteristics of color liquid crystal display devices. Further, it isdifficult to specify all of materials causative of display failurephenomena of color liquid crystal display devices. Even though all thematerials causative of display failure phenomena have been specified,the range of usable constituent materials is unfavorably significantlynarrowed when a resin composition free from any causative material is tobe used as the constituent material. Further, in this case, theproduction cost of the resin composition is increased.

[0008] Under these circumstances, the present invention has been made,and it is an object of the present invention to provide a resincomposition for a color filter, which can surely prevent the occurrenceof display failure phenomena of color liquid crystal display devices,can broaden the range of selection of usable constituent materials, anddoes not incur increased cost.

DISCLOSURE OF THE INVENTION

[0009] The present inventors have considered that a resin member forconstituting a color filter in contact with a liquid crystal layer in aliquid crystal display device is one of sources for the above-describedionic materials and have directed attention, as properties having acorrelation with display failures caused by ionic materials which havemigrated from the resin member into the liquid crystal layer, to voltageretention and residual DC (ΔE) of a liquid crystal after the extractionof impurities from components constituting a resin composition for aresin member.

[0010] In order to attain the above object, according to one aspect ofthe present invention, there is provided a resin composition for a colorfilter, comprising a combination of a volatile component with anonvolatile component, wherein:

[0011] not less than 50% by weight of the nonvolatile component isaccounted for by a first constituent, which, after the impurityextraction of a liquid crystal, permits the liquid crystal to have avoltage retention of not less than 60% and to have a residual DC (ΔE) ofnot more than 0.6 V; and

[0012] when less than 50% by weight of the nonvolatile component isaccounted for by a second constituent, which, after the impurityextraction of a liquid crystal, cannot permit the liquid crystal to havea voltage retention of not less than 60% and to have a residual DC (ΔE)of not more than 0.6 V, a requirement represented by formula (1) for therelation between the content of the second constituent and the voltageretention and a requirement represented by formula (2) for the relationbetween the content of the second constituent and the residual DC aresatisfied:

Content (wt %)÷voltage retention (%)<0.1  (1)

Content (wt %)×residual DC (V)<5  (2).

[0013] According to a preferred embodiment of the resin composition fora color filter according to the present invention, a photoreactivecompound as a sublimable component is further contained in the resincomposition.

[0014] Further, according to a preferred embodiment of the resincomposition for a color filter according to the present invention, thenonvolatile component comprises at least one member selected from apigment, a pigment derivative, and a surfactant.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a diagram showing a voltage-static capacitancehysteresis loop illustrating residual DC (ΔE); and

[0016]FIG. 2 is a schematic cross-sectional view showing one embodimentof a color filter.

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] The best mode for carrying out the invention will be described.

[0018] The resin composition for a color filter according to the presentinvention comprises a combination of a volatile component with anonvolatile component. Not less than 50% by weight of the nonvolatilecomponent is accounted for by a first constituent, which, after theimpurity extraction of a liquid crystal, permits the liquid crystal tohave a voltage retention of not less than 60% and to have a residual DC(ΔE) of not more than 0.6 V. The nonvolatile component may comprise twoor more constituents. When less than 50% by weight of the nonvolatilecomponent is accounted for by even one kind of a second constituent,which, after the impurity extraction of a liquid crystal, cannot providethe voltage retention and the residual DC (ΔE) falling within the aboverespective specific ranges, a requirement represented by formula (1) forthe relation between the content of the second constituent and thevoltage retention and a requirement represented by formula (2) for therelation between the content of the second constituent and the residualDC are satisfied:

Content (wt %)÷voltage retention (%)<0.1  (1)

Content (wt %)×residual DC (V)<5  (2).

[0019] When two or more second constituents are present, each secondconstituent should satisfy the requirements represented by formulae (1)and (2).

[0020] Thus, the present inventors have considered, as one of sourcesfor impurities such as ionic materials, a resin member for a colorfilter, which comes into contact with a liquid crystal layer in a liquidcrystal display device, and have directed attention, as propertieshaving a correlation with display failures caused by ionic materialswhich have migrated from the resin member into the liquid crystal layer,to voltage retention and residual DC (ΔE) of a liquid crystal after theextraction of impurities from components constituting a resincomposition for a resin member, and the present invention has been madebased on this.

[0021] Specifically, keeping the voltage applied across electrodeslocated on both sides of the liquid crystal layer is necessary from theviewpoint of preventing uneven whiteness as one of display failures,and, to this end, according to the present invention, in a resincomposition for a resin member, not less than 50% by weight of thenonvolatile component is accounted for by a first constituent, which,after the impurity extraction of a liquid crystal, permits the liquidcrystal to have a voltage retention of not less than 60%, preferably notless than 80%, and more preferably not less than 90%. On the other hand,in order to prevent sticking as another display failure, the residual DC(ΔE) should be minimized so that, when the voltage applied to the liquidcrystal layer is stopped, the continuation of the application ofunnecessary voltage to the liquid crystal layer is prevented. To thisend, according to the present invention, in the resin composition forthe resin member, not less than 50% by weight of the nonvolatilecomponent is accounted for by a constituent, which, after the impurityextraction of a liquid crystal, permits the liquid crystal to have aresidual DC (ΔE) of not more than 0.6 V, preferably not more than 0.2 V,more preferably not more than 0.1 V. When a second constituent, which,after the impurity extraction of a liquid crystal, cannot permit theliquid crystal to have the voltage retention and the residual DC (ΔE)respectively falling within the above specific ranges, is present in thenonvolatile component, the requirement represented by formula (1) forthe relation between the content of the second constituent and thevoltage retention and the requirement represented by formula (2) for therelation between the content of the second constituent and the residualDC are satisfied. By virtue of this constitution, a resin member formedof the resin composition according to the present invention, even whenbrought into contact with a liquid crystal layer in a color liquidcrystal display device, does not cause display failures such as stickingand uneven whiteness, and can realize a liquid crystal display devicehaving excellent display quality.

[0022] The impurity extraction, conditions for the measurement ofvoltage retention, and conditions for the measurement of residual DC(ΔE) will be described. (Impurity extraction)

[0023] 250 mg of a constituent is mixed in 10 g of ethanol. The mixedsolution is stirred at 21° C. for 30 min. 0.2 mL of this stirredsolution is transferred to a separate vessel, and the vessel is heatedat 105° C. to evaporate ethanol. Thereafter, 0.2 g of a liquid crystalis added dropwise to this vessel, and the liquid crystal is held at 105°C. for 5 hr to perform extraction. The liquid crystal used is one which,before the extraction of impurities, has a voltage retention of not lessthan 95% as measured under the following conditions for the measurementof voltage retention and a residual DC (ΔE) of not more than 0.05 V asmeasured under the following conditions for the measurement of residualDC (ΔE).

Conditions for Measurement of Voltage Retention

[0024] A measurement cell having a layer construction ofsubstrate/electrode/aligning layer/liquid crystal/ aligninglayer/electrode/substrate is provided. A liquid crystal, which has beensubjected to impurity extraction, is poured, followed by the measurementof voltage retention under the following conditions.

[0025] Electrode-electrode distance: 15 μm

[0026] Pulse amplitude of applied voltage: 5 V

[0027] Pulse frequency of applied voltage: 60 Hz

[0028] Pulse width of applied voltage: 16.67 msec

Conditions for Measurement of Residual DC (ΔE)

[0029] The residual DC (ΔE) is a voltage shift level (indicated by anarrow shown in FIG. 1) in a static capacitance defined by equation(CO+Cs)/2 determined from the maximum static capacitance (Cs) and theminimum static capacitance (CO) in a voltage-static capacitancehysteresis loop exemplified in FIG. 1. In the measurement, a measurementcell having a layer construction of substrate/electrode/aligninglayer/liquid crystal/aligning layer/electrode/substrate is provided. Aliquid crystal, which has been subjected to impurity extraction, ispoured, followed by the measurement of residual DC (ΔE) under thefollowing conditions.

[0030] Electrode-electrode distance: 15 μm

[0031] Liquid crystal used: a liquid crystal having a static capacitancesaturation voltage (indicated by Vs' in FIG. 1) of not more than 10 V

[0032] Measurement voltage range in voltage-static capacitancehysteresis loop: −10 V to +10 V.

[0033] Next, the components of the resin composition for a color filteraccording to the present invention will be described.

[0034] As described above, the resin composition for a color filteraccording to the present invention comprises at least a volatilecomponent and a nonvolatile component.

Nonvolatile Component

[0035] The nonvolatile component is composed mainly of a film formingresin, such as a binder resin or a monomer, and optionally contains apigment, a pigment dispersant, a pigment derivative, a surfactant andthe like. Among the following materials, materials satisfying the aboverequirements may be selected as the nonvolatile component.

[0036] Binder resins usable for the resin composition according to thepresent invention include ethylene-vinyl acetate copolymers,ethylene-vinyl chloride copolymers, ethylene-vinyl copolymers,polystyrene, acrylonitrile-styrene copolymers, ABS resins,polymethacrylic acid resins, ethylene-methacrylic acid resins, polyvinylchloride resins, chlorinated vinyl chloride, polyvinyl alcohol,cellulose acetate propionate, cellulose acetate butyrate, nylon 6, nylon66, nylon 12, polyethylene terephthalate, polybutylene terephthalate,polycarbonate, polyvinyl acetal, polyetherether ketone,polyethersulfone, polyphenylene sulfide, polyallylate, polyvinylbutyral, epoxy resins, phenoxy resins, polyimide resins, polyamide-imideresins, polyamic acid resins, polyetherimide resins, phenolic resins,and urea resins; polymers or copolymers produced from at least onepolymerizable monomer selected from methyl acrylate, methylmethacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate,n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate,sec-butyl acrylate, sec-butyl methacrylate, isobutyl acrylate, isobutylmethacrylate, tert-butyl acrylate, tert-butyl methacrylate, n-pentylacrylate, n-pentyl methacrylate, n-hexyl acrylate, n-hexyl methacrylate,2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, n-octyl acrylate,n-octyl methacrylate, n-decyl acrylate, n-decyl methacrylate, styrene,α-methylstyrene, N-vinyl-2-pyrrolidone, and glycidyl (meth)acrylate, andat least one member selected from acrylic acid, methacrylic acid, adimer of acrylic acid (for example, M-5600, manufactured by Toa GoseiChemical Industry Co., Ltd.), itaconic acid, crotonic acid, maleic acid,fumaric acid, and vinylacetic acid, and their acid anhydrides.

[0037] For example, polymers produced by adding a glycidyl- orhydroxyl-containing ethylenically unsaturated compound to the abovecopolymers may also be mentioned as the binder resin. However, it shouldbe noted that the binder resin is not limited to the above polymers orcopolymers.

[0038] Among the above binder resins, for example, polymethylmethacrylate resins, polyethyl methacrylate resins, methylmethacrylate-ethyl methacrylate copolymer resins, phenoxy resins, epoxyresins, polycarbonate resins, polystyrene resins, cellulose acetatepropionate, cellulose acetate butyrate, ethylhydroxyethylcellulose, andcellulose triacetate are preferred, for example, from the viewpoint ofcompatibility with a monomer used in combination with the binder resin.Particularly preferred are polymethyl methacrylate resins, polyethylmethacrylate resins, polystyrene resins, copolymers of mechacrylic acidwith styrene and glycidyl methacrylate, phenoxy resins, epoxy resins,and modification products thereof.

[0039] Epoxy resins, which are particularly preferred as the binderresin, include Epikote Series, manufactured by Yuka Shell Epoxy K.K.,CELLOXIDE Series and EPOLEAD Series, manufactured by Daicel ChemicalIndustries, Ltd., or bisphenol A epoxy resin, bisphenol F epoxy resin,bisphenol S epoxy resin, novolak type epoxy resin, polyglycidylcarboxylate, polyol glycidyl ester, aliphatic or alicyclic epoxy resin,amine epoxy resin, triphenolmethane type epoxy resin, dihydroxybenzenetype epoxy resin, and copolymer epoxy resin produced from glycidyl(meth)acrylate and a radically polymerizable monomer.

[0040] The content of the binder resin is preferably 10 to 90% byweight, more preferably 20 to 80% by weight, based on the nonvolatilecomponent of the resin composition.

[0041] The monomer for the resin composition according to the presentinvention may be at least one polymerizable compound having acarbon-carbon unsaturated bond. Specific examples thereof include: allylacrylate, benzyl acrylate, butoxyethyl acrylate, butoxyethylene glycolacrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, 2-ethylhexylacrylate, glycerol acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate,2-hydroxypropyl acrylate, isobornyl acrylate, isodecyl acrylate,isooctyl acrylate, lauryl acrylate, 2-methoxyethyl acrylate,methoxyethylene glycol acrylate, phenoxy ethyl acrylate, stearylacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate,1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanedioldiacrylate, 1,3-propanediol acrylate, 1,4-cyclohexanediol diacrylate,2,2-dimethylolpropane diacrylate, glycerol diacrylate, tripropyleneglycol diacrylate, glycerol triacrylate, trimethylolpropane triacrylate,polyoxyethylated trimethylolpropane triacrylate, pentaerythritoltriacrylate, pentaerythritol tetraacrylate, triethylene glycoldiacrylate, polyoxypropyl trimethylolpropane triacrylate, butyleneglycol diacrylate, 1,2,4-butanetriol triacrylate,2,2,4-trimethyl-1,3-pentanediol diacrylate, diallyl fumarate,1,10-decanediol dimethyl acrylate, and dipentaerythritol hexaacrylate;monomers wherein the acrylate group of the above compounds has beenreplaced with a methacrylate group;γ-methacryloxypropyltrimethoxysilane; 1-vinyl-2-pyrrolidone;2-hydroxyethyl acryloyl phosphate; acrylate monomers, such astetrahydrofurfuryl acrylate, dicyclopentenyl acrylate,dicyclopentenyloxyethyl acrylate, 3-butanediol diacrylate, neopentylglycol diacrylate, polyethylene glycol diacrylate, hydroxypivalic esterneopentyl glycol diacrylate, phenol-ethylene oxide-modified acrylate,phenol-propylene oxide-modified acrylate, N-vinyl-2-pyrrolidone,bisphenol A-ethylene oxide-modified diacrylate, pentaerythritoldiacrylate monostearate, tetraethylene glycol diacrylate, polypropyleneglycol diacrylate, trimethylolpropane propylene oxide-modifiedtriacrylate, isocyanuric acid-ethylene oxide-modified triacrylate,trimethylolpropane-ethylene oxide-modified triacrylate, pentaerythritolpentaacrylate, pentaerythritol hexaacrylate, and pentaerythritoltetraacrylate; monomers wherein the acrylate group of these acrylatemonomers has been replaced with a methacrylate group; (meth)acrylateoligomers, such as urethane acrylate oligomers comprising an acrylategroup bonded to an oligomer having a polyurethane structure, polyesteracrylate oligomers comprising an acrylate group bonded to an oligomerhaving a polyester structure, epoxy acrylate oligomers comprising anacrylate group bonded to an oligomer having an epoxy group, urethanemethacrylate oligomers comprising a methacrylate group bonded to anoligomer having a polyurethane structure, polyester methacrylateoligomers comprising a methacrylate group bonded to an oligomer having apolyester structure, and epoxy methacrylate oligomers comprising amethacrylate group bonded to an oligomer having an epoxy group; acrylategroup-containing polyurethane acrylates; acrylate group-containingpolyester acrylates, acrylate group-containing epoxy acrylate resins,methacrylate group-containing polyurethane methacrylates, methacrylategroup-containing polyester methacrylates, and methacrylategroup-containing epoxy methacrylate resins.

[0042] The above monomers are some examples of monomers usable in thepresent invention, and should not be construed as limiting the presentinvention. The content of the monomer is preferably 10 to 90% by weight,more preferably 20 to 80% by weight, based on the nonvolatile componentof the resin component.

[0043] When a pigment is contained as the nonvolatile component, forexample, conventional red pigments, yellow pigments, green pigments,blue pigments, violet pigments, and black pigments may be used as thepigment. Specific examples of pigments in terms of color index numberinclude: for red pigments, PR 177, PR 48:1, and PR 254; for yellowpigments, PY83, PY138, PY139, and PY150; for green pigments, PG 7 and PG36; for blue pigments, PB 15 and the like, PB 1, PB 19, PB 60, and PB61; and, for violet pigments, PV 23. Specific examples of black pigmentsinclude carbon black and metal oxide black pigments (titanium black andpigments containing oxides of copper, iron, manganese, vanadium, nickeland the like). The content of the pigment is preferably 10 to 60% byweight, more preferably 20 to 40% by weight, based on the nonvolatilecomponent of the resin composition.

[0044] When a pigment dispersant is contained as the nonvolatilecomponent, pigment dispersants usable herein include: polymericdispersants, such as modified polyurethanes, modified polyacrylates,modified polyesters, and modified polyamides; and surfactants, such asphosphoric esters, polyethers, and alkylamines. The content of thepigment dispersant is preferably 5 to 40% by weight, more preferably 10to 20% by weight, based on the nonvolatile component of the resincomposition.

[0045] When a pigment derivative is contained as the nonvolatilecomponent, pigment derivatives usable herein include: pigmentderivatives produced by adding a carboxyl group, a sulfonic acid group,an amino group, a carbonyl group, a sulfonyl group or the like to theskeleton of phthalocyanine, azo, anthraquinone, quinacridone or otherpigments; and salts of the above pigment derivatives. The content of thepigment derivative is preferably 1 to 10% by weight, more preferably 2to 5% by weight, based on the nonvolatile component of the resincomposition.

[0046] When a surfactant is contained as the nonvolatile component,surfactants usable herein include polyoxyethylene alkyl ethers, sorbitanfatty acid esters, polyoxyethylene alkylphenyl ethers, salts ofstraight-chain alkylbenzenesulfonic acids, and polyethylene glycol. Thecontent of the surfactant is preferably 1 to 10% by weight, morepreferably 2 to 5% by weight, based on the nonvolatile component of theresin composition.

Volatile Component

[0047] The resin composition according to the present invention containsa solvent as a volatile component. Examples of solvents usable hereininclude: alcohols, such as methanol, ethanol, n-propanol, isopropanol,ethylene glycol, and propylene glycol; terpenes, such as α- orβ-terpineol; ketones, such as acetone, methyl ethyl ketone,cyclohexanone, and N-methyl-2-pyrrolidone; aromatic hydrocarbons, suchas toluene, xylene, and tetramethylbenzene; glycol ethers, such ascellosolve, methyl cellosolve, ethyl cellosolve, carbitol, methylcarbitol, ethyl carbitol, butyl carbitol, propylene glycol monomethylether, propylene glycol monoethyl ether, dipropylene glycol monomethylether, dipropylene glycol monoethyl ether, triethylene glycol monomethylether, and triethylene glycol monoethyl ether; and acetic esters, suchas ethyl acetate, butyl acetate, cellosolve acetate, ethyl cellosolveacetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitolacetate, butyl carbitol acetate, propylene glycol monomethyl etheracetate, and propylene glycol monoethyl ether acetate.

Sublimable Component

[0048] The resin composition according to the present invention maycontain a photoreactive compound as a sublimable component in additionto the nonvolatile component and the volatile component. Examples ofphotoreactive compounds usable herein include: aromatic ketones, such asbenzophenone, Michler's ketone,N,N′-tetramethyl-4,4′-diaminobenzophenone,4-methoxy-4′-dimethylamino-benzophenone, 4,4′-diethylaminobenzophenone,2-ethylanthraquinone, and phenanthrene; benzoin ethers, such as benzoinmethyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzoins,such as methyl benzoin and ethyl benzoin; halomethylthiazole compounds,such as a dimer of 2-(o-chlorophenyl)-4,5-phenylimidazole, a dimer of2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole, a dimer of2-(o-fluorophenyl)-4,5-diphenylimidazole, a dimer of2-(o-methoxyphenyl)-4,5-diphenylimidazole, a dimer of2,4,5-triarylimidazole,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone,2-trichloromethyl-5-styryl-1,3,4-oxadiazole,2-trichloromethyl-5-(p-cyanostyryl)-1,3,4-oxadiazole, and2-trichloromethyl-5-(p-methoxystyryl)-1,3,4-oxadiazole;halomethyl-S-triazine compounds, such as2,4-bis(trichloromethyl)-6-p-methoxystyryl-S-triazine,2,4-bis(trichloromethyl)-6-(1-p-dimethylaminophenyl-1,3-butadienyl)-S-triazine,2-trichloromethyl-4-amino-6-p-methoxystyryl-S-triazine,2-(naphtho-1-yl)-4,6-bis-trichloromethyl-S-triazine,2-(4-ethoxy-naphtho-1-yl)-4,6-bis-trichloromethyl-S-triazine, and2-(4-butoxy-naphtho-1-yl)-4,6-bis-trichloromethyl-S-triazine; andphotopolymerization initiators, such as2,2-dimethoxy-1,2-diphenylethan-1-one,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone,1,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,1-hydroxy-cyclohexyl-phenylketone,Irgacure 369 (manufactured by Ciba-Geigy), Irgacure 651 (manufactured byCiba-Geigy), and Irgacure 907 (manufactured by Ciba-Geigy). According tothe present invention, these photoreactive compounds may be used aloneor as a mixture of two or more.

[0049] The content of the sublimable component is 5 to 40 parts byweight, preferably 10 to 20 parts by weight, based on 100 parts byweight of the nonvolatile component of the resin composition.

[0050] The resin composition according to the present invention may beused to form a colored layer, a black matrix (a light shielding layer),a protective layer, a gap holding material and the like of a colorfilter.

[0051]FIG. 2 is a schematic cross-sectional view showing one embodimentof a color filter. In FIG. 2, a color filer 11 comprises: a substrate12; and, provided on the substrate 12, a black matrix 13 and a coloredlayer 14 (a red pattern 14R, a green pattern 14G, and a blue pattern 14Barranged in a desired pattern form). A transparent resin protectivelayer 15 is provided so as to cover the black matrix 13 and the coloredlayer 14. Further, a transparent gap holding material 16 is provided ata plurality of predetermined sites in the black matrix 13 so as toprotrude from the resin protective layer 15.

[0052] This color filter 11, after the provision of a common transparentelectrode layer and an aligning layer on the resin protective layer 15,is used in a liquid crystal display device. In this case, the resinprotective layer 15 and the gap holding material 16 are in positionswhich come into contact with a liquid crystal layer. When at least theresin protective layer 15 and the gap holding material 16 are formed ofthe resin composition according to the present invention, the occurrenceof display failures such as sticking and uneven whiteness can beprevented and, thus, a liquid crystal display device having excellentdisplay quality can be realized.

[0053] In the color filter 11, when the transparent protective layer 15is not provided, or when the colored layer 14 comes into contact withthe liquid crystal layer even in the case where the transparentprotective layer 15 is present, the colored layer 14 may be formed ofthe resin composition according to the present invention. When the blackmatrix 13 is exposed in a portion between adjacent patterns of thecolored layer 14 and thus comes into contact with the liquid crystallayer in the liquid crystal display device, the black matrix 13 may beformed of the resin composition according to the present invention.

EXAMPLES

[0054] The present invention will be described in more detail withreference to the following examples.

Preparation of Resin Compositions (1) Resin Compositions for ColoredLayer

[0055] Beads were added to a composition in a dispersion form(containing a pigment, a pigment derivative, a dispersant, a surfactant,and a solvent). The mixture was dispersed by means of a dispergator for3 hr, and the beads were then removed therefrom to prepare a dispersion.The dispersion was mixed with a clear resist composition (containing abinder resin, a monomer, an additive, a photopolymerization initiator,and a solvent). Thus, resin compositions for respective color patterns,that is, a resin composition R for a red pattern, a resin composition G1for a green pattern, a resin composition G2 for a green pattern, a resincomposition B1 for a blue pattern, and a resin composition B2 for a bluepattern, were prepared. The formulations of the resin compositions wereas follows. A paint shaker was used as the dispergator. (Resincomposition R for red pattern) • Red pigment (Cromophtal Red A2B, . . .4.8 pts.wt. manufactured by Ciba-Geigy) • Yellow pigment (PaliotolYellow . . . 1.2 pts.wt. D1819, manufactured by BASF) • Dispersant(Solsperse 24000, . . . 3.0 pts.wt. manufactured by Zeneca Co., Ltd.) •Monomer (SR399, manufactured by . . . 4.0 pts.wt. Sartomer) • Binderresin: polymer 1 . . . 5.0 pts.wt. • Initiator (Irgacure 907, . . . 1.4pts.wt. manufactured by Ciba-Geigy) • Initiator (2,2′-bis(o-chloro- . .. 0.6 pt.wt. phenyl)-4,5,4′,5′-tetraphenyl- 1,2′-biimidazole) • Solvent(propylene glycol . . . 80.0 pts.wt. monomethyl ether acetate) (Resincomposition G1 for green pattern) • Green pigment (Monastral Green 9Y-C,. . . 4.2 pts.wt. manufactured by Zeneca Co., Ltd.) • Yellow pigment(Paliotol Yellow . . . 1.8 pts.wt. D1819, manufactured by BASF) •Dispersant (Solsperse 24000, . . . 3.0 pts.wt. manufactured by ZenecaCo., Ltd.) • Monomer (SR399, manufactured by . . . 4.0 pts.wt. Sartomer)• Binder resin: polymer 1 . . . 5.0 pts.wt. • Initiator (Irgacure 907, .. . 1.4 pts.wt. manufactured by Ciba-Geigy) • Initiator(2,2′-bis(o-chloro- . . . 0.6 pt.wt. phenyl)-4,5,4′,5′-tetraphenyl-1,2′-biimidazole) • Solvent (propylene glycol . . . 80.0 pts.wt.monomethyl ether acetate) (Resin composition G2 for green pattern) •Green pigment (Monastral Green 6Y-CL, . . . 4.2 pts.wt. manufactured byZeneca Co., Ltd.) • Yellow pigment (Paliotol Yellow . . . 1.8 pts.wt.D1819, manufactured by BASF) • Dispersant (Solsperse 24000, . . . 3.0pts.wt. manufactured by Zeneca Co., Ltd.) • Monomer (SR399, manufacturedby . . . 4.0 pts.wt. Sartomer) • Binder resin: polymer 1 . . . 5.0pts.wt. • Initiator (Irgacure 907, . . . 1.4 pts.wt. manufactured byCiba-Geigy) • Initiator (2,2′-bis(o-chloro- . . . 0.6 pt.wt.phenyl)-4,5,4′,5′-tetraphenyl- 1,2′-biimidazole) • Solvent (propyleneglycol . . . 80.0 pts.wt. monomethyl ether acetate) (Resin compositionB1 for blue pattern) • Blue pigment (Heliogen Blue L6700F, . . . 6.0pts.wt. manufactured by BASF) • Pigment derivative (Solsperse 12000, . .. 0.6 pt.wt. manufactured by Zeneca Co., Ltd.) • Dispersant (Solsperse24000, . . . 2.4 pts.wt. manufactured by Zeneca Co., Ltd.) • Monomer(SR399, manufactured by . . . 4.0 pts.wt. Sartomer) • Binder resin:polymer 1 . . . 5.0 pts.wt. • Initiator (Irgacure 907, . . . 1.4 pts.wt.manufactured by Ciba-Geigy) • Initiator (2,2′-bis(o-chloro- . . . 0.6pt.wt. phenyl)-4,5,4′,5′-tetraphenyl- 1,2′-biimidazole) • Solvent(propylene glycol . . . 80.0 pts.wt. monomethyl ether acetate) (Resincomposition B2 for blue pattern) • Blue pigment (Heliogen Blue L6700F, .. . 6.0 pts.wt. manufactured by BASF) • Pigment derivative (Solsperse5000, . . . 0.6 pt.wt. manufactured by Zeneca Co., Ltd.) • Dispersant(Solsperse 24000, . . . 2.4 pts.wt. manufactured by Zeneca Co., Ltd.) •Monomer (SR399, manufactured by . . . 4.0 pts.wt. Sartomer) • Binderresin: polymer 1 . . . 5.0 pts.wt. • Initiator (Irgacure 907, . . . 1.4pts.wt. manufactured by Ciba-Geigy) • Initiator (2,2′-bis(o-chloro- . .. 0.6 pt.wt. phenyl)-4,5,4′,5′-tetraphenyl- 1,2′-biimidazole) • Solvent(propylene glycol . . . 80.0 pts.wt. monomethyl ether acetate) Thepolymer 1 was prepared by adding 16.9% by mole of 2-methacryloyloxyethylisocyanate to 100% by mole of a copolymer of benzyl methacrylate :styrene : acrylic acid : 2-hydroxyethyl methacrylate = 15.6 : 37.0 :30.5 : 16.9 (molar ratio), and had a weight average molecular weight of42500. The same is true of the polymer 1 used in the following otherresin compositions. (2) Resin composition for protective layer The resincomposition for a protective layer was prepared according to thefollowing formulation. (Resin composition for protective layer) •Monomer (SR399, manufactured by . . . 7.1 pts.wt. Sartomer) • Binderresin: polymer 1 . . . 8.8 pts.wt. • Binder resin: epoxy resin (Epikote. . . 9.7 pts.wt. 180 S70, manufactured by Yuka Shell Epoxy K.K.) •Initiator (Irgacure 907, . . . 1.4 pts.wt. manufactured by Ciba-Geigy) •Initiator (2,2′-bis(o-chloro- . . . 1.0 pt.wt.phenyl)-4,5,4′,5′-tetraphenyl- 1,2′-biimidazole) • Solvent (dimethyldiglycol) . . . 38.0 pts.wt. • Solvent (3-methoxybutyl acetate) . . .34.0 pts.wt. (3) Resin composition for gap holding material Two resincompositions S1 and S2 for a gap holding material were preparedaccording to the following formulations. (Resin composition S1 for gapholding material) • Monomer (SR399, manufactured by . . . 8.7 pts.wt.Sartomer) • Binder resin: polymer 1 . . . 10.9 pts.wt. • Binder resin:epoxy resin (Epikote . . . 12.1 pts.wt. 180 S70, manufactured by YukaShell Epoxy K.K.) • Surfactant (Nonion HS-210, . . . 1.0 pt.wt.manufactured by Nippon Oils & Fats Co., Ltd.) • Initiator (Irgacure 369,. . . 1.2 pts.wt. manufactured by Ciba-Geigy) • Initiator(2,2′-bis(o-chloro- . . . 1.0 pt.wt. phenyl)-4,5,4′,5′-tetraphenyl-1,2′-biimidazole) • Solvent (propylene glycol monomethyl . . . 29.1pts.wt. ether acetate) • Solvent (3-methoxybutyl acetate) . . . 36.0pts.wt. (Resin composition S2 for gap holding material) • Monomer(SR399, manufactured by . . . 8.7 pts.wt. Sartomer) • Binder resin:polymer 1 . . . 10.9 pts.wt. • Binder resin: epoxy resin (Epikote . . .12.1 pts.wt. 180 S70, manufactured by Yuka Shell Epoxy K.K.) •Surfactant (Nonion HS-210, . . . 2.0 pts.wt. manufactured by Nippon Oils& Fats Co., Ltd.) • Initiator (Irgacure 369, . . . 1.2 pts.wt.manufactured by Ciba-Geigy) • Initiator (2,2′-bis(o-chloro- . . . 1.0pt.wt. phenyl)-4,5,4′,5′-tetraphenyl- 1,2′-biimidazole) • Solvent(propylene glycol monomethyl . . . 28.1 pts.wt. ether acetate) • Solvent(3-methoxybutyl acetate) . . . 36.0 pts.wt.

Impurity Extraction and Measurement of Voltage Retention and Residual DC(ΔE)

[0056] For each of the constituents (monomer, binder resin, pigment,pigment derivative, dispersion, and surfactant) of the nonvolatilecomponent in each of the resin compositions, impurity extraction withrespect to a liquid crystal (MLC-6847, manufactured by Merck) wascarried out by the following method, and the liquid crystal was thenmeasured for the voltage retention and the residual DC (ΔE) under thefollowing conditions for measurement. The results are shown in Tables 1to 8 below.

[0057] The liquid crystal used was such that, before the impurityextraction, the voltage retention as measured under the followingconditions for the measurement of voltage retention was not less than98% and the residual DC (ΔE) as measured under the following conditionsfor the measurement of residual DC (ΔE) was not more than 0.01 V.

Impurity Extraction Method

[0058] 250 mg of a constituent was mixed in 10 g of ethanol. The mixedsolution was stirred at 21° C. for 30 min. 0.2 mL of this stirredsolution was transferred to a separate vessel, and the vessel was heatedat 105° C. to evaporate ethanol. Thereafter, 0.2 g of a liquid crystalwas added dropwise to this vessel, and the liquid crystal was held at105° C. for 5 hr to perform extraction.

Conditions for Measurement of Voltage Retention

[0059] A measurement cell having a layer construction ofsubstrate/electrode/aligning layer/liquid crystal/aligninglayer/electrode/substrate was provided. A liquid crystal, which had beensubjected to impurity extraction, was poured, followed by themeasurement of voltage retention under the following conditions.

[0060] Electrode-electrode distance: 15 μm

[0061] Pulse amplitude of applied voltage: 5 V

[0062] Pulse frequency of applied voltage: 60 Hz

[0063] Pulse width of applied voltage: 16.67 msec

Conditions for Measurement of Residual DC (ΔE)

[0064] A measurement cell having a layer construction ofsubstrate/electrode/aligning layer/liquid crystal/ aligninglayer/electrode/substrate was provided. A liquid crystal, which had beensubjected to impurity extraction, was poured, followed by themeasurement of residual DC (ΔE) under the following conditions. Here theresidual DC (ΔE) is a voltage shift level (indicated by an arrow shownin FIG. 1) in a static capacitance defined by equation (CO+Cs) /2determined from the maximum static capacitance (Cs) and the minimumstatic capacitance (CO) in a voltage-static capacitance hysteresis loop.

[0065] Electrode-electrode distance: 15 μm

[0066] Liquid crystal used: a liquid crystal having a static capacitancesaturation voltage (indicated by Vs' in FIG. 1) of not more than 10 V

[0067] Measurement voltage range in voltage-static capacitancehysteresis loop: −10 V to +10 V. TABLE 1 (Resin composition R for redpattern) Voltage Content in retention, Residual nonvolatile Constituents% DC,V component, % Non- Red pigment 98 0.01 26.7 volatile Yellowpigment 86 0.59 6.7 component Dispersant 94 0.03 16.7 Monomer 91 0.1022.2 Binder resin 98 0.01 27.8

[0068] As is apparent from Table 1, for the resin composition R for ared pattern, all the constituents of the nonvolatile component were suchthat, after the impurity extraction, the liquid crystal had a voltageretention of not less than 60% and a residual DC (ΔE) of not more than0.6 V. TABLE 2 (Resin composition G1 for green pattern) Voltage Contentin retention, Residual nonvolatile Constituents % DC,V component, % Non-Green pigment 79 0.23 23.3 volatile Yellow pigment 86 0.59 10.0component Dispersant 94 0.03 16.7 Monomer 91 0.10 22.2 Binder resin 980.01 27.8

[0069] As is apparent from Table 2, for the resin composition G1 for agreen pattern, all the constituents of the nonvolatile component weresuch that, after the impurity extraction, the liquid(crystal had avoltage retention of not less than 60% and a residual DC (ΔE) of notmore than 0.6 V. TABLE 3 (Resin composition G2 for green pattern)Voltage Content in retention, Residual nonvolatile Constituents % DC,Vcomponent, % Non- Green pigment 18 1.98 23.3 volatile Yellow pigment 860.59 10.0 component Dispersant 94 0.03 16.7 Monomer 91 0.10 22.2 Binderresin 98 0.01 27.8

[0070] As is apparent from Table 3, for the resin composition G2 for agreen pattern, 76.7% by weight of the nonvolatile component wasaccounted for by constituents (yellow pigment, dispersant, monomer, andbinder resin) such that, after the impurity extraction, the liquidcrystal had a voltage retention of not less than 60% and a residual DC(ΔE) of not more than 0.6 V. The green pigment occupying the remaining23.3% by weight of the nonvolatile component did not satisfy therequirements for the voltage retention and the residual DC (ΔE).Therefore, an examination was done on whether or not the green pigmentsatisfies the requirement represented by formula (1) for the relationbetween the content of the green pigment and the voltage retention andthe requirement represented by formula (2) for the relation between thecontent of the green pigment and the residual DC. As a result, as isapparent from the following calculations, it was confirmed that thegreen pigment did not satisfy both the requirement represented byformula (1) and the requirement represented by formula (2).

Content (wt %)÷voltage retention (%)<0.1  (1)

23.3 (wt %)÷18(%)=1.29>0.1

Content (wt %)×residual DC (V)<5  (2)

23.3 (wt %)×1.98 (V)=46.1>5

[0071] TABLE 4 (Resin composition B1 for blue pattern) Voltage Contentin retention, Residual nonvolatile Constituents % DC,V component, % Non-Blue pigment 98 0.01 33.3 volatile Pigment 95 0.01 3.3 componentderivative Dispersant 94 0.03 13.3 Monomer 91 0.10 22.2 Binder resin 980.01 27.8

[0072] As is apparent from Table 4, for the resin composition B1 for ablue pattern, all the constituents of the nonvolatile component weresuch that, after the impurity extraction, the liquid crystal had avoltage retention of not less than 60% and a residual DC (ΔE) of notmore than 0.6 V. TABLE 5 (Resin composition B2 for blue pattern) VoltageContent in retention, Residual nonvolatile Constituents % DC,Vcomponent, % Non- Blue pigment 98 0.01 33.3 volatile Pigment 0.1 2.273.3 component derivative Dispersant 94 0.03 13.3 Monomer 91 0.10 22.2Binder resin 98 0.01 27.8

[0073] As is apparent from Table 5, for the resin composition B2 for ablue pattern, 96.7% by weight of the nonvolatile component was accountedfor by constituents (blue pigment, dispersant, monomer, and binderresin) such that, after the impurity extraction, the liquid crystal hada voltage retention of not less than 60% and a residual DC (ΔE) of notmore than 0.6 V. The pigment derivative occupying the remaining 3.3% byweight of the nonvolatile component did not satisfy the requirements forthe voltage retention and the residual DC (ΔE). Therefore, anexamination was done on whether or not the pigment derivative satisfiesthe requirement represented by formula (1) for the relation between thecontent of the pigment derivative and the voltage retention and therequirement represented by formula (2) for the relation between thecontent of the pigment derivative and the residual DC. As a result, asis apparent from the following calculations, it was confirmed that thepigment derivative did not satisfy both the requirement represented byformula (1) and the requirement represented by formula (2).

3.3 (wt %)÷0.1(%)=33>0.1

3.3 (wt %)×2.27 (V)=7.49>5

[0074] TABLE 6 (Resin composition for protective layer) Content inVoltage Residual nonvolatile Constituents retention, % DC, V component,% Non- Monomer 91 0.1 27.7 volatile Binder resin 96 0.01 34.4 component(polymer 1) Binder resin 98 0.01 37.9 (epoxy resin)

[0075] As is apparent from Table 6, for the resin composition for aprotective layer, all the constituents of the nonvolatile component weresuch that, after the impurity extraction, the liquid crystal had avoltage retention of not less than 60% and a residual DC (ΔE) of notmore than 0.6 V. TABLE 7 (Resin composition S1 for gap holding material)Content in Voltage Residual nonvolatile Constituents retention, % DC, Vcomponent, % Non- Monomer 91 0.10 26.6 volatile Binder resin 98 0.0133.3 component (polymer 1) Binder resin 98 0.01 37.0 (epoxy resin)Surfactant 53 0.93 3.1

[0076] As is apparent from Table 7, for the resin composition S1 for agap holding material, 96.9% by weight of the nonvolatile component wasaccounted for by constituents (blue pigment, dispersant, monomer, andbinder resin) such that, after the impurity extraction, the liquidcrystal had a voltage retention of not less than 60% and a residual DC(ΔE) of not more than 0.6 V. The surfactant occupying the remaining 3.1%by weight of the nonvolatile component did not satisfy the requirementsfor the voltage retention and the residual DC (ΔE). Therefore, anexamination was done on whether or not the surfactant satisfies therequirement represented by formula (1) for the relation between thecontent of the surfactant and the voltage retention and the requirementrepresented by formula (2) for the relation between the content of thesurfactant and the residual DC. As a result, as is apparent from thefollowing calculations, it was confirmed that the surfactant satisfiedboth the requirement represented by formula (1) and the requirementrepresented by formula (2).

3.1 (wt %)÷53(%)=0.06<0.1

3.1 (wt %)×0.93 (V)=2.88<5

[0077] TABLE 8 (Resin composition S1 for gap holding material) Contentin Voltage Residual nonvolatile Constituents retention, % DC, Vcomponent, % Non- Monomer 91 0.10 25.8 volatile Binder resin 98 0.0132.3 component (polymer 1) Binder resin 98 0.01 35.9 (epoxy resin)Surfactant 53 0.93 5.9

[0078] As is apparent from Table 8, for the resin composition S2 for agap holding material, 94.1% by weight of the nonvolatile component wasaccounted for by constituents (blue pigment, dispersant, monomer, andbinder resin) such that, after the impurity extraction, the liquidcrystal had a voltage retention of not less than 60% and a residual DC(ΔE) of not more than 0.6 V. The surfactant occupying the remaining 5.9%by weight of the nonvolatile component did not satisfy the requirementsfor the voltage retention and the residual DC (ΔE). Therefore, anexamination was done on whether or not the surfactant satisfies therequirement represented by formula (1) for the relation between thecontent of the surfactant and the voltage retention and the requirementrepresented by formula (2) for the relation between the content of thesurfactant and the residual DC. As a result, as is apparent from thefollowing calculations, it was confirmed that the surfactant did notsatisfy both the requirement represented by formula (1) and therequirement represented by formula (2).

5.9÷53=0.11>0.1

5.9×0.93=5.49>5

Preparation of Color Filter Preparation of Sample 1

[0079] A glass substrate having a size of 100 mm×100 mm and a thicknessof 0.7 mm (7059 glass, manufactured by Corning) was provided as asubstrate for a color filter. This substrate was cleaned according to aconventional method. A resin composition having the followingformulation for a black matrix was coated on the whole area of one sideof the substrate, followed by mask exposure, development, and postbaking to form a black matrix (thickness: 1.2 μm). (Resin compositionfor black matrix) • Black pigment (TM Black #9550, . . . 14.0 pts.wt.manufactured by Dainichiseika Color & Chemicals Manufacturing Co., Ltd.)• Dispersant (Disperbyk 111, . . . 1.2 pts.wt. manufactured byBik-Chemie) • Polymer (VR60, manufactured by . . . 2.8 pts.wt. ShowaHigh Polymer Co., Ltd.) • Monomer (SR399, manufactured by . . . 3.5pts.wt. Sartomer) • Additive (L-20, manufactured by Soken . . . 0.7pt.wt. Chemical Engineering Co., Ltd.) • Initiator(2-benzyl-2-dimethylamino- . . . 1.6 pts.wt.1-(4-morpholinophenyl)-butanone-1) • Initiator (4,4′-diethylamino- . . .0.3 pt.wt. benzophenone) • Initiator (2,4-diethylthioxanthone) . . . 0.1pt.wt. • Solvent (ethylene glycol . . . 75.8 pts.wt. monobutyl ether)

[0080] Next, three resin compositions R, G1, and B1 having the aboverespective formulations for a colored layer were used to form a coloredlayer. Specifically, a resin composition R for a red pattern was spincoated on the whole area of the substrate with a black matrix formedthereon. Thus, a photosensitive resin layer for red was formed, and wasthen prebaked at 90° C. for 3 min. Thereafter, the photosensitive resinlayer for red was subjected to alignment exposure using a photomask fora predetermined color pattern, followed by development with a developingsolution (a 0.05% aqueous KOH solution) and then post-baking at 200° C.for 30 min to form a red pattern (thickness: 1.5 μm) at predeterminedpositions relative to the black matrix pattern.

[0081] A green pattern (thickness: 1.5 μm) was formed at predeterminedpositions relative to the black matrix pattern in the same manner asused in the formation of the red pattern, except that the resincomposition G1 for a green pattern was used. Further, a blue pattern(thickness: 1.5 μm) was formed at predetermined positions relative tothe black matrix pattern in the same manner as used in the formation ofthe red pattern, except that the resin composition B1 for a blue patternwas used.

[0082] Thus, a color filter (sample 1) was prepared which had astructure provided with a colored layer formed so as to cover the blackmatrix (the same structure as shown in FIG. 2, except that theprotective layer and the gap holding material were removed).

Preparation of Sample 2

[0083] A color filter (sample 2) was prepared in the same manner as usedin the preparation of the sample 1, except that the three resincompositions R, G2, and B1 having the above formulations were used asthe resin compositions for a colored layer.

Preparation of Sample 3

[0084] A color filter (sample 3) was prepared in the same manner as usedin the preparation of the sample 1, except that the three resincompositions R, G1, and B2 having the above formulations were used asthe resin compositions for a colored layer.

Preparation of Sample 4

[0085] A black matrix was first formed in the same manner as used in thepreparation of the sample 1. Next, a colored layer was formed in thesame manner as used in the preparation of the sample 1, except that thethree resin compositions R, G2, and B2 having the above respectiveformulations were used. The resin composition for a protective layerhaving the above formulation was then spin coated so as to cover theblack matrix and the colored layer, followed by drying to form a 1.5μm-thick protective layer. Thus, a color filter (sample 4) was preparedwhich had the same structure as shown in FIG. 2, except that the gapholding material was removed.

Preparation of Sample 5

[0086] The resin composition S1 having the above formulation for a gapholding material was spin coated so as to cover the protective layer inthe color filter (sample 4), and the coating was prebaked at 90° C. for3 min, followed by exposure using a predetermined photomask for a gapholding material and development with a developing solution (a 0.01%aqueous KOH solution). Subsequently, post-baking was carried out at 200°C. for 30 min, whereby a plurality of gap holding materials having aheight of 5 μm were formed. Thus, a color filter (sample 5) having astructure as shown in FIG. 2 was prepared.

Preparation of Sample 6

[0087] A color filer (sample 6) was prepared in the same manner as usedin the preparation of the sample 5, except that the resin composition S2having the above formulation was used as the resin composition for a gapholding material.

Preparation of Liquid Crystal Display Device

[0088] A transparent common electrode of indium tin oxide (ITO) wasformed on each of the color filters (samples 1 to 6).

[0089] Separately, a glass substrate having a size of 100 mm×100 mm anda thickness of 0.7 mm (7059 glass, manufactured by Corning) was providedas a transparent substrate. This substrate was cleaned according to aconventional method. Thereafter, a thin film transistor (TFT) was formedon the substrate at its plurality of predetermined sites. A transparentpixel electrode of indium tin oxide (ITO) was formed so as to beconnected to each TFT in its drain electrode. Thus, a counter electrodesubstrate was prepared.

[0090] Next, a polyimide resin coating composition was coated so as tocover the color filter on its transparent common electrode and thetransparent pixel electrode in the counter electrode substrate, and thecoating was then dried to form an aligning layer (thickness: 0.07 μm),followed by aligning treatment.

[0091] Liquid crystal display devices (samples 1 to 6) were thenprepared using these color filters and counter electrode substrates. Inthis case, MLC-6847 manufactured by Merck was used as a liquid crystal.

Evaluation of Liquid Crystal Display Devices

[0092] For the six liquid crystal display devices (samples 1 to 6) thusprepared, image display was continuously carried out under conditions oftemperature 20 to 25° C. and relative humidity (RH) 60 to 80% for 72 hr,and the display quality was evaluated according to the followingcriteria. The results are shown in Table 9.

Evaluation Criteria of Display Quality

[0093] ◯: Neither sticking nor uneven whiteness occurred, that is, thedisplay quality was very good.

[0094] X: Sticking and uneven whiteness occurred, that is, displayfailure phenomena were observed. TABLE 9 Coating composition CoatingLiquid crystal Black for colored layer Protective Composition forQuality of display device matrix Red Green Blue layer columnar convexdisplay Sample 1 Provided R G1 B1 Not provided — ◯ Sample 2 Provided RG2 B1 Not provided — X Sample 3 Provided R G1 B2 Not provided — X Sample4 Provided R G2 B2 Provided — ◯ Sample 5 Provided R G2 B2 Provided S1 ◯Sample 6 Provided R G2 B2 Provided S2 X

[0095] As is apparent from Table 9, for the liquid crystal displaydevices of samples 1, 4, and 5 wherein, among resin members constitutingthe color filter incorporated in the liquid crystal display device, theresin member located at a position, which comes into contact with theliquid crystal layer, had been formed using the resin compositionaccording to the present invention, any display failure phenomenon didnot occur even in display for a long period of time.

[0096] By contrast, for both the liquid crystal display device of sample2 wherein the green pattern, in the colored layer of the color filter,which comes into contact with the liquid crystal layer, had not beenformed using the resin composition according to the present invention,and the liquid crystal display device of sample 3 wherein the bluepattern, in the colored layer of the color filter, which comes intocontact with the liquid crystal layer, had not been formed using theresin composition according to the present invention, sticking anduneven whiteness occurred, that is, display failure phenomena wereobserved.

[0097] Further, for the liquid crystal display device of sample 6wherein the gap holding material, in the color filter, which comes intocontact with the liquid crystal layer, had not been formed using theresin composition according to the present invention, sticking anduneven whiteness occurred, that is, display failure phenomena wereobserved.

[0098] As is apparent from the foregoing detailed description, accordingto the present invention, not less than 50% by weight of the nonvolatilecomponent in the resin composition for a color filter is accounted forby a constituent which, after impurity extraction, permits a liquidcrystal to have a voltage retention and a residual DC (ΔE) fallingwithin respective specific ranges. When the nonvolatile componentcontains a constituent which, after impurity extraction, cannot permitthe liquid crystal to have a voltage retention and a residual DC (ΔE)falling within respective specific ranges, the requirement for aspecific relation between the content of this constituent and thevoltage retention and the requirement for a specific relation betweenthe content of this constituent and the residual DC are satisfied. Byvirtue of this constitution, a resin member, constituting the colorfilter, which has been formed using the resin composition according tothe present invention, when brought into contact with a liquid crystallayer in a color liquid crystal display device, does not cause displayfailures, such as sticking and uneven whiteness, and thus can realizeliquid crystal display devices possessing excellent display quality.Further, for each constituent of the nonvolatile component, a materialsatisfying the above specific conditions is selected and used, and,thus, the range of selection of usable constituent materials can bebroadened.

1. A resin composition for a color filter, comprising a combination of avolatile component with a nonvolatile component, wherein: not less than50% by weight of the nonvolatile component is accounted for by a firstconstituent, which, after the impurity extraction of a liquid crystal,permits the liquid crystal to have a voltage retention of not less than60% and to have a residual DC (ΔE) of not more than 0.6 V; and when lessthan 50% by weight of the nonvolatile component is accounted for by asecond constituent, which, after the impurity extraction of a liquidcrystal, cannot permit the liquid crystal to have a voltage retention ofnot less than 60% and to have a residual DC (ΔE) of not more than 0.6 V,a requirement represented by formula (1) for the relation between thecontent of the second constituent and the voltage retention and arequirement represented by formula (2) for the relation between thecontent of the second constituent and the residual DC are satisfied:Content (wt %)÷voltage retention (%)<0.1  (1)Content (wt %)+residual DC(V)<5  (2)
 2. The resin composition for a color filter according toclaim 1 , which further comprises a photoreactive compound as asublimable component.
 3. The resin composition for a color filteraccording to claim 1 or 2 , wherein the nonvolatile component comprisesat least one member selected from a pigment, a pigment derivative, and asurfactant.